High temperature and room temperature tribological behaviors of in-situ carbides reinforced Ni-based composites by reactive sintering Ni and Ti2AlC precursor

The in-situ carbides reinforced Ni-based composites were fabricated by reactive hot-pressing sintering Ni and Ti2AlC powders. Tribological performance and mechanisms at room temperature and 800 °C were studied. Sintered composites contain Ni-based solid solution, Ni2TiAl, Ni3Al, TiCx, Ti3NiAl2C and Al2O3. At room temperature, the elastic modulus, hardness and H/E of composites enhanced due to the increase of carbides, resulting in wear rate declined with the rise of Ti2AlC. At 800 °C, because of the formation of reducing-friction and anti-wear oxide layers consisting of TiO2, NiO, Al2O3, NiTiO3, and NiAl2O4, wear rate was further decreased to 4.2 × 10−6 mm3/Nm. Composition differences on the surface between worn and static oxidized at 800 °C show that tribo-chemical reaction promotes the generation of NiO and NiTiO3.